Hitachi, Ltd.

Kouji Sonoda

Naoki Utsunomiya

Naoto Matsunami

Takashi Oeda

Masaaki Iwasaki

Manabu Kitamura

Yutaka Takata

Satoshi Yoshizawa

Hiroyuki Chiba

Masahiko Yamauchi

Hiroyuki Matsumoto

Hiroshi Tani

Toshinori Ono

Mitsuhiro Shoda

Hiroyuki Kumazaki

Toshiya Kurakake

A storage systemincluding multiple slots for loading a block I/O interface controller, a file I/O interface controller, and any other kinds of interface controllers that are combined freely. The storage systemincludes a management table that manages fail-over-enabled devices by grouping those devices in accordance with the interface type and the domain to which each device belongs; an information table that directs a fail-over procedure; and fail-over controlling means that takes over the processing of a failed interface controller belonging to a fail-over-enabled group. The fail-over system offers several modalities for monitoring failures, selecting takeover controllers and restoring functionality. Storage systemsolves conventional problems by providing a system that can mount a plurality of file systems, and that resists multiple failures detected in a fail-over server.

Fail-over storage system

The object of this invention is to provide a magnetic disk which has an excellent durability even with a protective film having a small film thickness of 4 nm or less. The magnetic disk of this invention is a magnetic disk comprising a non-magnetic substrate and, provided thereon, a magnetic metal film, carbon protective film and fluorine-containing lubricant film, wherein the carbon protective film is a DLC film having a film thickness of 4 nm or less and the ratio of infrared absorption intensity resulting from the C&mdash;H bond near 2,920 cm determined by FT-IR using ATR to infrared absorption intensity resulting from the C&mdash;F bond of the lubricant film is 0.035-0.060.

Magnetic disk having ultrathin carbon protective film and magnetic disk apparatus

In collective I/O processing in which a plurality of processes access the same file in a shared manner, when each user process issues an I/O request, the user process notifies the system of information on a file region accessed by all the processes; information for specifying whether or not a prefetch is performed, and information for specifying whether or not a disk preallocate is performed, together with the I/O requests issued by all associated processes, as hint information. The system provides a buffer for storing data in a file region accessed by all the processes based on the hint information, such that the I/O processing for all the processes is performed using this buffer.

File I/O control method

In a computer system in which nodes are connected to each other via a network, transmission and reception buffers of sender and receiver processes are prepared as resident areas in a main storage. A node of a receiver side notifies, prior to initiation of a communication, a physical address of a data reception area of the node to a node on a sender side. In the node on the sender side, the reported physical address is added to transmission data to transfer a resultant item. On the receiver side, reception data is written in a location of the main storage at the physical address. In the receiver node, the double buffering is employed to prevent an overwriting operation of another node onto the data reception area. The respective nodes achieve partial synchronization with adjacent nodes in chain, thereby automatically establishing synchronization between all nodes. A node on a receiver side notifies prior to initiation of a communication an identifier of a data reception area to a node on a sender side such that the sender node transmits data with the identifier added thereto. In the receiver node, the identifier added to the received data is compared with an identifier added to a data reception area thereof. If mismatching results, interruption is caused in a processor of the receiver node.

Method for interprocessor communication

Method for intraprocessor communication

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Tokyo, Japan

Kouji Sonoda